Working vehicle

ABSTRACT

The working vehicle includes an engine installed in a front portion of a traveling machine body, and a post-processing device configured to purify exhaust gas from the engine. The post-processing device is mounted on an upper side of the engine. The engine and the post-processing device are covered with a hood. A hood shield plate is disposed on a rear surface side of the hood and covers at least the post-processing device from a rear surface. A heat insulating layer is formed between an operating seat disposed on a rear side of the hood and the hood shield plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation from U.S. application Ser. No.15/362,562 filed Nov. 28, 2016, which is a continuation fromInternational Application No. PCT/JP2015/063890 filed May 14, 2015,which claims priority to JP Application No. 2014-111314 filed May 29,2014, the entire contents of each application is incorporated herein byreference without disclaimer.

BACKGROUND OF THE INVENTION

The invention according to the present application relates to a workingvehicle.

Recently, enactment of strict emission regulation on diesel engines hasled to increased demands for installing a post-processing device, suchas an exhaust gas purifying device, in a farm work machine, aconstruction machine, a vessel, and the like including the dieselengine. The post-processing device executes purification processing forair pollutants in exhaust gas. In some conventional working vehicles,such as a tractor, the exhaust gas purifying device is disposed togetherwith the diesel engine in an engine compartment below the hood, to beinstalled in the vehicle (see Japanese Unexamined Patent ApplicationPublication No. 2013-116692).

In the working vehicle such as a tractor, a pair of fuel tanks, storingfuel supplied to the engine, are respectively disposed on left and rightsides of a vehicle body to make space for the engine, a transmission,and the like (see Japanese Unexamined Patent Application Publication No.2010-042779).

SUMMARY OF THE INVENTION

When the diesel engine provided with the exhaust gas treatment devicedescribed above is employed in the working vehicle such as a tractor,not only the diesel engine and the exhaust gas treatment device but alsoa radiator, a battery, and electronic components for the exhaust gastreatment device need to be crammed in a small and limited installationspace.

In the installation space of the working vehicle, when the diesel engineis driven, the diesel engine emits heat, and thus temperature of thediesel engine itself as well as the exhaust gas purifying device becomesextremely high. Thus, the temperature in the engine compartment needs tobe adjusted so that adverse effect of the heat emitted from the dieselengine and the exhaust gas treatment device can be prevented. All thingsconsidered, appropriate arrangement and cooling structures need to bepursued. Furthermore, heating of a driver's seat, disposed on the rearside of the engine compartment, needs to be reduced or else, comfort ofan operator in the cabin is compromised.

When the post-processing device such as the exhaust gas purifying deviceis installed, a large engine compartment space is required. Thus, a hoodbecomes large, requiring a highly rigid opening/closing structure. Theload is especially concentrated on a fulcrum position when the hood isopened, and thus a highly rigid rotatably supporting mechanism ispreferably provided. Furthermore, the inside of the engine compartmentis required to be easily accessed for performing a maintenance work andthe like.

A technical object of the invention according to the present applicationis to provide an improved working vehicle in view of the currentsituation described above.

The invention according to the present application is a working vehicleincluding: an engine installed in a front portion of a traveling machinebody; and a post-processing device configured to purify exhaust gas fromthe engine. The post-processing device is mounted on an upper side ofthe engine. The engine and the post-processing device are covered with ahood. A hood shield plate is disposed on a rear surface side of the hoodand covers at least the post-processing device from a rear surface. Aheat insulating layer is formed between an operating seat disposed on arear side of the hood and the hood shield plate.

In the working vehicle according to the invention according to thepresent application, the post-processing device may be disposed inparallel with an output shaft of the engine. The hood shield plate mayinclude: a first shield surface that is disposed on one side of the hoodand covers a rear side of the post-processing device; a second shieldsurface extending forward from a side edge of the first shield surface;and a third shield surface that extends toward another side of the hoodfrom a front edge of the second shield surface. On the rear surface ofthe hood, an open space may be provided between the third shield surfaceof the hood shield plate and the other side of the hood, and an exhaustpipe connected to an exhaust side of the post-processing device mayextend toward the rear side of the hood.

In the working vehicle according to the invention according to thepresent application, the hood shield plate may have recesses andprotrusions formed at a predetermined interval to block sound generatedfrom an engine compartment below the hood.

In the working vehicle, the hood shield plate covering a rear side ofthe engine may be fixed to the traveling machine body to be disposed onthe rear surface of the hood. A heat shield plate may be disposedbetween the hood and the post-processing device. The hood may pivotabout an upper end position of the hood shield plate to be opened andclosed.

In this configuration, the hood shield plate may be disposed while beingseparated from a front side of the operating seat disposed on the rearside of the hood. Beam frames in parallel with the traveling machinebody may be disposed on both sides on a front surface of the hood shieldplate. The hood may include: a hinge having a pivoting portion connectedto a rear end position of the hood; and a damper that has one endconnected to a front side of the hood and makes a telescopic movement. Afixed portion of the hinge may be connected to a hood supporting portionprovided on an upper edge side of the hood shield plate. Another end ofthe damper may be rotatably supported by the beam frame.

In the working vehicle, a radiator for cooling the engine with water anda cooling fan for cooling the engine and the radiator with air areprovided. The cooling fan may be disposed on a front surface side of theengine. The radiator may be disposed on a front side of the cooling fan.The post-processing device may be mounted on the upper side of theengine. The radiator, the cooling fan, the engine, and thepost-processing device may be covered with the hood. Cooling air may betaken into the hood through a front grille formed on the front surfaceof the hood, by driving the cooling fan. Openings may be formed in bothleft and right side portions of the hood. Shielding plates may bedisposed at positions close to left and right side portions of theradiator.

In this configuration, the radiator may stand on a front portion of thetraveling machine body. A fan shroud surrounding the cooling fan may beattached to a rear surface side of the radiator. When the hood isclosed, the shielding plates provided to the hood may be in contact withboth left and right side portions of the fan shroud. An opening may befurther formed on the ceiling portion of the hood. The fan shroud mayhave an upper surface provided with an upper shielding portion thatextends in a left and right direction and left and right surfacesprovided with a pair of left and right side shielding portions extendingin an upper and lower direction. When the hood is closed, the uppershielding portion may be disposed close to a back surface of the hoodceiling portion, and the side shielding portions may be in contact withthe shielding plates of the hood. The openings on the ceiling portionand the both left and right side portions of the hood may be disposedmore on a front side than the fan shroud.

In the working vehicle, engine covers formed of a porous plate may beprovided on left and right rear lower sides of the hood. The enginecover may have an upper end position positioned below thepost-processing device. Thus, air heated by the engine and thepost-processing device may be discharged outside, while achieving a hightemperature maintaining effect for the post-processing device with thehood, so that a regeneration operation can be performed under hightemperature.

In the embodiment of the invention according to the present application,heat from an engine compartment below the hood is shielded by the hoodshield plate. The operating seat can be prevented from being heated byexhaust heat from the engine compartment. Thus, an operator on theoperating seat can comfortably operate the vehicle without beingaffected by exhaust heat from the engine and the post-processing device.The operating seat and the hood are separated from each other. Thus, thehood may have a large outer dimension and can still be sufficientlyopened. As described above, even when the engine compartmentincorporates a heat emitting member such as the post-processing device,with a large volume achieved in the hood, the hood can be less affectedby heat emitted from the post-processing device.

The hood shield plate has first to third shield surfaces bent in a crankshape. Thus, rear and side portions of the post-processing device as theheat emitting member shield are shielded, whereby the operating seat onthe rear side of the engine compartment can be less affected by theheat. An open space is provided between the third shield surface that isrelatively less affected by heat and the hood. Thus, a tail pipe can bedisposed at a position less likely to involve an operation of gettingON/OFF the vehicle by the operator. The third shield surface that isrelatively less affected by heat is positioned on the front side. Thus,components such as a hydraulic pump can be disposed in a large spaceextending toward the operating seat.

The hood shield plate is provided with the recesses and the protrusions.Thus, noise generated from the engine in the engine compartment can beattenuated by the recesses and the protrusions of the hood shield plateso as not to be transmitted to the operating seat.

In the embodiment of the invention according to the present application,the heat shield plate is disposed above the post-processing device,whereby the hood can be prevented from being heated by heat emitted fromthe post-processing device and the engine. The space is formed betweenthe hood and the heat shield plate. Thus, the post-processing device canbe operated in a high temperature environment, while insulating theinside of the engine compartment below the heat shield plate from outerair. The operating seat can be prevented from being heated by the heatemitted from the engine compartment, with the heat in the enginecompartment under the hood shielded by the hood shield plate. With a gapprovided between the hood shield plate and the heat shield plate, theheat is less likely to accumulate in the engine compartment. Thus, theheat damage on the post-processing device itself, the hood, and the likecan be prevented.

In the embodiment of the invention according to the present application,the hood pivots about the upper end position of the hood shield plate tobe opened and closed. Thus, the hood can be largely opened rearward, sothat the operator can easily access inside the engine compartment. Allthings considered, the operator can not only perform a maintenance workeasily but can also perform the maintenance safely and the like by beingprevented from coming into contact with the hood.

In the embodiment of the invention according to the present application,the heat in the engine compartment below the hood is shielded by thehood shield plate. Thus, the operating seat can be prevented from beingheated by heat emitted from the engine compartment, whereby the operatoron the operating seat can comfortably operate the vehicle without beingaffected by exhaust heat from the engine and the post-processing device.The operating seat and the hood are separated from each other. Thus, thehood may have a large outer dimension and can still be sufficientlyopened. As described above, even when the engine compartmentincorporates a heat emitting member such as the post-processing device,with a large volume achieved in the hood, the hood can be less affectedby heat emitted from the post-processing device.

In the embodiment of the invention according to the present application,the engine covers having an entire surface in a porous form are disposedon both sides of the engine. Thus, the air heated by the engine and thepost-processing device can be discharged outside. The engine cover hasan upper end position positioned below the post-processing device. Thus,a high temperature maintaining effect for the post-processing device canbe achieved with the hood, so that a regeneration operation can beperformed under high temperature.

In the embodiment of the invention according to the present application,the heat in the engine compartment below the hood is shielded by thehood shield plate. Thus, the operating seat can be prevented from beingheated by heat emitted from the engine compartment, whereby the operatoron the operating seat can comfortably operate the vehicle without beingaffected by exhaust heat from the engine and the post-processing device.The space is formed between the hood and the heat shield plate. Thus,the post-processing device can be operated in a high temperatureenvironment, while insulating the inside of the engine compartment belowthe heat shield plate from outer air.

In the embodiment of the invention according to the present application,a flow of the cooling air taken in through the openings on the side ofthe radiator toward the rear side is shielded by the shielding plate, sothat the cooling air can be sent to the front surface side of theradiator. Thus, an amount of cooling air passing through the radiatorcan be increased, whereby the radiator can efficiently be cooled by air.The cooling air is efficiently blown to the engine by the cooling fansurrounded by the fan shroud. Thus, a relaxed heat environment can beachieved around the engine even when the post-processing device thatserves as a high temperature heat source is provided.

In the embodiment of the invention according to the present application,when the hood is closed, the shielding plate and the side shieldingportions are positioned on the rear side of the opening on the sidesurface, and the upper shielding portion is positioned on the rear sideof the opening of the ceiling portion. Thus, a large amount of coolingair can be taken into the radiator. Thus, a high effect of coolingvarious cooling members such as the radiator and an intercooler disposedon the front side of the engine compartment can be achieved. A largeamount of cooling air can be taken in by the cooling fan surrounded bythe fan shroud. Thus, the cooling air can be supplied to the engine thatserves as the heat emitting member, whereby an excellent heat balancecan be achieved in the engine compartment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is as a left side view of a tractor;

FIG. 2 is a plan view of the tractor;

FIG. 3 is a right side view of the tractor;

FIG. 4 is a front view of the tractor;

FIG. 5 is a diagram illustrating a left side surface of a travelingmachine body;

FIG. 6 is a diagram illustrating a right side surface of the travelingmachine body;

FIG. 7 is a perspective view of the traveling machine body as diagonallyviewed from a left and rear side;

FIG. 8 is a perspective view of the traveling machine body as diagonallyviewed from a right and rear side;

FIG. 9 is a perspective view illustrating a hood rear surface structureas viewed from a side of a cabin;

FIG. 10 is an enlarged view of a left side surface of the tractor;

FIG. 11 is a perspective view illustrating a structure of an enginecompartment as diagonally viewed from the left rear side;

FIG. 12 is a perspective view illustrating a structure of an enginecompartment frame as diagonally viewed from a right rear side;

FIG. 13 is a perspective view illustrating a structure of the enginecompartment frame as diagonally viewed from a left lower side;

FIG. 14 is a perspective view illustrating the structure of the enginecompartment as diagonally viewed from a right front side;

FIG. 15 is a perspective view illustrating the structure of the enginecompartment as diagonally viewed from the left rear side;

FIG. 16 is an exploded perspective view illustrating a structure of anopening and closing supporting mechanism of a hood;

FIG. 17 is a cross-sectional plan view illustrating a structure in thehood;

FIG. 18 is a cross-sectional side view illustrating the structure in thehood;

FIG. 19 is a diagram illustrating the hood as viewed from a rearsurface;

FIG. 20 is a diagram illustrating the hood as viewed from a bottomsurface;

FIG. 21 is a diagram illustrating the tractor as viewed from the leftside surface in a state where the hood is open;

FIG. 22 is a diagram illustrating a supporting structure for the hood;and

FIG. 23 is a perspective view illustrating the structure in the enginecompartment in the state where the hood is open.

DETAILED DESCRIPTION

An embodiment of the invention according to the present application isdescribed below with reference to the drawings, with a tractor as anexample of a working vehicle.

First of all, an overview of a tractor 1 is described with reference toFIG. 1 to FIG. 8. A traveling machine body 2 of the tractor 1 accordingto the embodiment is supported by a pair of left and right front wheels3 and a pair of left and right rear wheels 4 as traveling units. Adiesel engine 5 (hereinafter, simply referred to as an engine) of acommon rail type, serving as a driving source, is installed in a frontportion of the traveling machine body 2 and drives the rear wheels 4 andthe front wheels 3 to make the tractor 1 travel forward and backward.The engine 5 is covered by a hood 6. A cabin 7 is disposed on an uppersurface of the traveling machine body 2. The cabin 7 incorporates anoperating seat 8 and a steering wheel (circular steering wheel) 9. Asteering direction of the front wheels 3 moves left and right bysteering the steering wheel 9. Steps 10 with which an operator gets onand off the vehicle are provided to an outer lower portion of the cabin7. Fuel tanks 11 from which fuel is supplied to the engine 5 areprovided below a bottom portion of the cabin 7.

The traveling machine body 2 includes: an engine frame 14 including afront bumper 12 and a front axle casing 13; and left and right vehiclebody frames 15 detachably fixed to a rear portion of the engine frame14. A front axle 16 rotatably protrudes outward from both left and rightends of the front axle casing 13. The front wheels 3 are attached to theboth left and right ends of the front axle casing 13 via the front axle16. A transmission case 17 is coupled to the rear portions of thevehicle body frames 15. The transmission case 17 shifts the rotarydriving force from the engine 5 as appropriate, and transmits the forceto the four front and rear wheels 3, 3, 4, and 4. A tank frame 18 havinga rectangular plate shape in bottom view and protruding outward towardthe left and the right is fastened to a lower surface side of thetransmission case 17 and the left and the right vehicle body frames 15with bolts. In this embodiment, the fuel tanks 11 include two left andright tanks. The left and the right fuel tanks 11 are respectivelymounted on the upper surface sides of the left and the right protrudingportions of the tank frame 18. Left and right rear axle cases 19 aremounted to left and right outer side surfaces of the transmission case17 while protruding outward. Left and right rear axles 20 are rotatablyinserted in the left and the right rear axle cases 19. The rear wheels 4are attached to the transmission case 17 via the rear axles 20. The leftand the right rear wheels 4 have upper sides covered with left and rightrear fenders 21.

A hydraulic hoisting and lowering mechanism 22 that hoists and lowers awork machine such as a rotary tiller for example is detachably attachedto an upper surface of a rear portion of the transmission case 17. Thework machine such as a rotary tiller is coupled to the rear portion ofthe transmission case 17 via a three-point link mechanism including apair of left and right lower links 23 and a top link 24. A power-takeoff (PTO) shaft 25 protrudes rearward from a rear side surface of thetransmission case 17 and is used for transmitting a PTO driving force tothe work machine such as a rotary tiller.

A flywheel 26 is attached to be directly coupled to an engine outputshaft (not illustrated) that protrudes rearward from a rear side surfaceof the engine 5. A main driving shaft 27 protruding rearward from theflywheel 26 and a main transmission input shaft 28 protruding forwardfrom a front surface side of the transmission case 17 are coupled toeach other via a driving force transmission shaft 29 including universaljoints on both ends. The transmission case 17 incorporates a hydrauliccontinuously variable transmission, a forward/backward travelingswitching mechanism, a traveling sub-transmission gear mechanism, and arear wheel differential gear mechanism. The rotary driving force fromthe engine 5 is transmitted to the main transmission input shaft 28 ofthe transmission case 17 via the main driving shaft 27 and the drivingforce transmission shaft 29, and appropriate shifting is achieved withthe hydraulic continuously variable transmission and the travelingsub-transmission gear mechanism. The shifted driving force istransmitted to the left and the right rear wheels 4 via the rear wheeldifferential gear mechanism.

A front wheel output shaft 30 protruding forward from a lower portion ofa front surface of the transmission case 17 is coupled to a front wheeltransmission shaft (not illustrated) protruding rearward from the frontaxle casing 13 incorporating a front wheel differential gear mechanism(not illustrated), via a front wheel driving shaft 31. The shifteddriving force, obtained by the hydraulic continuously variabletransmission and the traveling sub-transmission gear mechanism in thetransmission case 17, is transmitted to the left and the right frontwheels 3 from the front wheel output shaft 30, the front wheel drivingshaft 31 and the front wheel transmission shaft, via the front wheeldifferential gear mechanism in the front axle casing 13.

Next, an internal structure of the cabin 7 is described with referenceto FIG. 5 to FIG. 10 and FIG. 17. A steering column 32 is disposed on afront side of the operating seat 8 in the cabin 7. The steering column32 stands while being buried on a rear surface side of a dashboard 33disposed on a front surface side in the cabin 7. The steering wheel 9having a substantially circular shape in plan view is attached to anupper end side of a steering shaft protruding upward from an uppersurface of the steering column 32.

The diesel engine 5 has a cylinder head mounted on a cylinder blockincorporating the engine output shaft and pistons. An intake manifold203 is disposed on a right side surface of the cylinder head and anexhaust manifold 204 is disposed on a left side surface of the cylinderhead. Thus, in the engine 5, the intake manifold 203 and the exhaustmanifold 204 are respectively disposed on both side surfaces along theengine output shaft. The cylinder block in the diesel engine 5 has afront surface provided with a cooling fan 206 and a rear surfaceprovided with the flywheel 26. Thus, the flywheel 26 and the cooling fan206 are respectively disposed on both side surfaces orthogonal to theengine output shaft in the engine 5.

The diesel engine 5 has a right side surface provided with: a fuelsupply pump 207 for supplying fuel; a cylindrical common rail 208through which the fuel is pumped to an injector; a fuel filter 209 thatremoves foreign objects from the fuel from the fuel tank 11; and anexhaust gas recirculation (EGR) device 210 coupled to the intakemanifold 203. The fuel in the fuel tanks 11 is supplied by a fuel pump213 to the fuel supply pump 207 via the fuel filter 209, and then ispumped to the common rail 208 from the fuel supply pump 207. Thus, thehigh pressure fuel is accumulated in the common rail 208, and injectedfrom each injector to a corresponding cylinder of the engine 5, withfuel injection valves of the injectors each controlled to be opened andclosed.

The diesel engine 5 has a left side surface provided with: a turbosupercharger 211 that compresses air with exhaust gas from the exhaustmanifold 204; and an EGR cooler 212 with which the exhaust gas from theexhaust manifold 204 is partially cooled and recirculated to the EGRdevice 210. The turbo supercharger 211 includes a compressor caseincorporating a blower wheel. The compressor case has an intake airintake side connected to an intake air exhaust side of an air cleaner221 via an intake pipe 222, and has an intake air exhaust side connectedto an intake air relaying pipe (on an intake air upstream side) 223. Theturbo supercharger 211 includes a turbine case incorporating a turbinewheel. The turbine case has an exhaust air intake side coupled to anexhaust gas outlet of the exhaust manifold 204, and has an intake airexhaust side coupled to an exhaust gas inlet of an exhaust gas purifyingdevice 224 as a post-processing device.

The EGR cooler 212 and the EGR device 210 respectively disposed on bothside surfaces of the diesel engine 5 are connected to each other via arecirculation exhaust gas pipe 214 serving as a recirculation pipe pathcircumventing a rear surface (side of the flywheel 26) of the engine 5.The EGR device 210 is connected to an intake air relaying pipe (on anintake air downstream side) 225 extending forward (toward the coolingfan 206) on a right side of the engine 5. The intake air relaying pipes223 and 225 are respectively disposed on the both side surfaces of thediesel engine 5, and extend forward and upward from the diesel engine 5to be connected to an intercooler (not illustrated) disposed in a frame226 on a front side of the diesel engine 5. The air cleaner 221 isdisposed on an upper side of a front surface of the frame 226. Theintake pipe 222 connected to the air cleaner 221 extends toward the rearside of the left side surface of the diesel engine 5 in such a manner asto be formed over the frame 226.

In the configuration described above, fresh air (outer air) taken intothe air cleaner 221 is subjected to dust removal and purification in theair cleaner 221, and then is sucked into the compressor case of theturbo supercharger 211 via the intake pipe 222. The fresh air iscompressed in the compressor case of the turbo supercharger 211 to bepressurized fresh air, and is supplied to an EGR main body case of theEGR device 210 via the intake air relaying pipes 223 and 225 and theintercooler. A part (EGR gas) of the exhaust gas from the exhaustmanifold 204 is cooled by the EGR cooler 212 and then is supplied to theEGR main body case of the EGR device 210 via the recirculation exhaustgas pipe 214.

The EGR device 210 mixes the pressurized fresh air from the turbosupercharger 211 and the EGR gas from the exhaust manifold 204, and thensupplies the resultant mixed gas to the intake manifold 203. In thismanner, the part of the exhaust gas discharged from the diesel engine 5to the exhaust manifold 204 is recirculated to the intake manifold 203.Thus, the maximum fuel temperature at the time of high load driving isreduced, and an amount of nitrogen oxide (NOx) discharged from thediesel engine 5 is reduced.

The diesel engine 5 includes the continuously regenerating exhaust gaspurifying device 224 (diesel particulate filter (DPF)). The exhaust gaspurifying device 224 removes particulate matters (PM) in exhaust gasdischarged from the engine 5, and reduces carbon oxide (CO) andhydrocarbons (HC) in the exhaust gas. The exhaust gas purifying device224 is disposed at a portion on an upper surface side of the dieselengine 5 above the exhaust manifold 204. The exhaust gas purifyingdevice 224 has a substantially cylindrical shape extending in a frontand rear direction in parallel with the output shaft (crank shaft) ofthe diesel engine 5. The exhaust gas purifying device 224 has theexhaust gas inlet and an exhaust gas outlet on both sides in the frontand rear direction (upstream and downstream sides in the exhaust gasmovement direction).

The exhaust gas purifying device 224 has a casing outer circumferencesurface on one end side (rear side) in a longitudinal direction providedwith the exhaust gas inlet. The exhaust gas inlet is coupled to anexhaust gas exhaust side of the turbine case of the turbo supercharger211. The exhaust gas purifying device 224 has a casing outercircumference surface on the other end side (front side) in thelongitudinal direction provided with the exhaust gas outlet coupled toan exhaust pipe 227. The exhaust gas purifying device 224 has theexhaust gas inlet opened toward the lower side, and has the exhaust gasoutlet opened toward right upper side. The exhaust pipe 227 is disposedto extend from the front left side to the rear right side of the dieselengine 5 while being disposed over the diesel engine 5.

An exhaust gas relaying bracket 215 forming a supporting member (DPFsupporting member) of the exhaust gas purifying device 224 has a lowerend side fastened to the exhaust manifold 204 with bolts. The exhaustgas relaying bracket 215 has an upper portion side in which an exhaustgas relaying pipe, serving as an exhaust gas relaying path, is formed.The exhaust gas relaying bracket 215 has an exhaust gas intake side ofthe exhaust gas relaying pipe fastened to the exhaust air discharge sideof the turbine case in the turbo supercharger 211 with bolts, and has anexhaust air discharge side of the exhaust gas relaying pipe 85 fastenedto an exhaust gas inlet of the exhaust gas purifying device 224. Thus,the exhaust manifold 204 and the exhaust gas purifying device 224 arecommunicated with each other via the turbine case of the turbosupercharger 211 and the exhaust gas relaying pipe of the exhaust gasrelaying bracket 215.

The engine 5 includes an outlet side bracket member 216 and an inletside bracket member 217 that serve as housing supporting members thatsupport and fix the exhaust gas purifying device 224. The outlet sidebracket member 216 and the inlet side bracket member 217 respectivelystand from front and rear surface sides of the cylinder head of theengine 5 that are orthogonal to the engine output shaft. The inlet sidebracket member 217 is positioned on the rear surface side of the engine5, and supports the exhaust air intake side of the exhaust gas purifyingdevice 224. The outlet side bracket member 216 is positioned on thefront surface side of the engine 5, and supports an exhaust airdischarge side of the exhaust gas purifying device 224.

The inlet side bracket member 217 has a lower end side fastened to therear surface of the cylinder head of the engine 5 with bolts, and has anupper end side fastened to an inlet side lid member of the exhaust gaspurifying device 224 via a relaying bracket 219. A part of a lower endsside rear surface of the inlet side bracket member 217 is protruded, anda supporting plate 218 is fastened to the protruding portion. The inletside bracket member 217 and the supporting plate 218 are arranged in thefront and rear direction and are coupled to each other. Thus, a spacefor installing the recirculation exhaust gas 214 coupling between theEGR device 210 and the EGR cooler 212 can be provided between the inletside bracket member 217 and the supporting plate 218 withoutcompromising the supporting strength of the exhaust gas purifying device224.

The exhaust gas purifying device 224 and the exhaust pipe 227 arearranged above the diesel engine 5 side by side in a left and rightdirection while being in parallel with the output shaft of the dieselengine 5. More specifically, the exhaust gas purifying device 224 andthe exhaust pipe 227 are arranged side by side in such a manner that theexhaust gas purifying device 224 covers the left side of the uppersurface of the diesel engine 5 and the exhaust pipe 227 covers the rightside of the upper surface of the diesel engine 5.

The exhaust pipe 227 connected to an exhaust side of the exhaust gaspurifying device 224 is connected to a tail pipe 229 via a bellows pipe228 standing on the rear and right side of the diesel engine 5. The tailpipe 229 has a shape of extending from the lower side to the upper sideon the front and right side of the cabin 7, and being bent toward thediesel engine 5 on the lower side of the cabin 7. The tail pipe 229 hasthe lower bent portion formed to extend from the inner side to the outerside to be formed over the vehicle body frame 15. The tail pipe 229 iscovered with a heat shield plate 230 except for an upper end portion.

Next, a configuration in an engine compartment frame below the hood 6 isdescribed with reference to FIG. 5 to FIG. 18. A front grille 231 isformed on a lower side of a front portion of the hood 6, and covers afront side of the engine compartment. Engine covers 232 formed of porousplates are disposed on left and right lower sides of the hood 6 to coverleft and right sides of the engine compartment. Thus, the hood 6 and theengine covers 232 cover the front, upper, left, and right sides of thediesel engine 5.

The pair of left and right engine frames 14 have front end side innerside surfaces coupled to left and right outer side surfaces of an axlecase coupling member 295. The axle case coupling member 295 has a lowerside provided with a coupling portion at four corners on front andrear-left and right sides protruding downward, and is coupled to thefront axle casing 13, whereby the front axle casing 13 is supportedwhile being suspended from the engine frame 14. The front bumper 12 iscoupled to a front surface of the axle case coupling member 295 to bedisposed at the position to be in contact with a front end surface ofthe engine frame 14.

A frame bottom plate 233 is bridged between the upper edges of the leftand the right engine frames 14 and the upper surface of the front bumper12 to cover the front end side upper side of the engine frame 14. Theframe bottom plate 233 has a lower surface coupled to side surfaces ofthe left and the right engine frames 14 via coupling brackets 233 a. Thecoupling brackets 233 a disposed on the left and the right sides eachhave one end coupled to the side surface of the engine frame 14 and hasthe other end coupled to a side edge side of the lower surface of theframe bottom plate 233. An under cover 296 covering the lower front sideof the engine 5 is disposed on the rear end of the frame bottom plate233. The under cover 296 has a front end coupled to the frame bottomplate 233 and has rear left and right side edges respectively coupled tothe left and the right engine frames 14. The under cover 296 includes: afront side portion extending from the rear end of the frame bottom plate233 toward the lower end of the engine frame 14; and a rear side portionextending forward on the lower side of the engine 5.

A radiator 235 having a rear surface side on which a fan shroud 234 isattached stands on the frame bottom plate 233 to be positioned on thefront surface side of the engine 5. The fan shroud 234 surrounds theouter circumference side of the cooling fan 206, and communicatesbetween the radiator 235 and the cooling fan 206. The fan shroud 234includes: an upper shielding portion 234 a having an upper end with a Tshaped cross-section; and side shielding portions 234 b protruding fromthe left and the right side surfaces. The upper shielding portion 234 ais disposed to extend in the left and right direction over the entirearea of the upper surface of the fan shroud 234, and has an upper enddisposed close to the lower surface of a ceiling portion 259 of the hood6, when the hood 6 is closed. The pair of left and right side shieldingportions 234 b are disposed to extend in an upper and lower directionover the entire area of the left and the right side surfaces of the fanshroud 234, and have left and right ends disposed close to the innerside surfaces of side portions of the hood 6, when the hood 6 is closed.

The frame 226 having a rectangular frame shape stands on the framebottom plate 233 on the front surface side of the radiator 235. Theframe 226, the radiator 235, and the fan shroud 234 are arranged in thisorder from the front side at positions above the axle case couplingmember 295 bridging between the left and the right engine frames 14. Theframe 226 has a rear surface covered with the radiator 235, and has afront surface as well as left and right side surfaces covered with amesh plate member. The intercooler described above, oil and fuelcoolers, and the like are disposed in the frame 226. The air cleaner 221is disposed at an upper position of the front surface of the frame 226.Thus, cooling air taken in through the front grille 231 flows toward theframe 226 behind the front grille 231. Thus, the air cleaner 221, theintercooler, and the oil and the fuel coolers in the frame 226 arecooled. The cooling air from the front side reaches the radiator 235disposed on the rear surface of the frame 226, whereby a higher effectof cooling the cooling water supplied to the diesel engine 5 isachieved.

The left and the right vehicle body frames 15 have front end sidescoupled to rear end sides of the left and the right engine frames 14 viaa spacer 297, and are arranged to clamp the left and the right engineframes 14. The pair of left and right vehicle body frames 15 is coupledto each other via a supporting beam frame 236. Coupling surfaces (outerside surfaces) of the supporting beam frame 236 to be coupled with thevehicle body frame 15 are on the same plane as coupling surfaces (outerside surfaces) of the spacer 297 to be coupled with the vehicle bodyframes 15. The supporting beam frame 236 is fastened to each of the leftand the right vehicle body frames 15 with bolts, and bridges between theleft and the right vehicle body frames 15. An engine supporting frame237 is mounted on the upper surface of the supporting beam frame 236.The engine supporting frame 237 has a lower end surface fastened to anupper surface of the supporting beam frame 236 with bolts, and thus hasa shape surrounding the flywheel 26 of the diesel engine 5 together withthe supporting beam frame 236.

The diesel engine 5 has engine leg attachment portions (notillustrated), provided to lower sides of left and right side surfaces,coupled to engine supporting brackets 298 disposed at intermediateportions of the pair of left and right engine frames 14, via engine legmembers 238 each including an anti-vibration rubber piece 239. Thediesel engine 5 has engine leg attachment portions (not illustrated),provided on the rear surface, coupled to the upper surface of the enginesupporting frame 237 via engine leg members 240 each including ananti-vibration rubber piece 241.

The engine leg members 238 are fastened with bolts to the upper portionsof the engine supporting brackets 298 coupled to outer sides of theintermediate portions of the pair of left and right engine frames 14with the anti-vibration rubber piece 239 provided on the lower side.With the pair of left and right engine leg members 238, the engineframes 14 clamp the diesel engine 5, whereby the front side of thediesel engine 5 is supported. The diesel engine 5 has a rear surfacecoupled to front end sides of the pair of left and right vehicle bodyframe 15, via the supporting beam frame 236, the engine supporting frame237, and the engine leg member 240, whereby the rear side of the dieselengine 5 is supported by the front ends of the vehicle body frames 15.The diesel engine 5 is supported to the traveling machine body 2 withthe left and the right front anti-vibration rubber pieces 239 and theleft and the right rear anti-vibration rubber pieces 241.

A pair of left and right column frames 242 and 243 stand on the uppersurface of the engine supporting frame 237 in such a manner as tosandwich the engine leg members 240 from left and right. Morespecifically, the left side column frame 242 stands at a left rear sideposition of the engine leg member 240 via a supporting bracket 242 a.The right side column frame 243 stands at a right front side position ofthe engine leg member 240 via a supporting bracket 243 a. The supportingbracket 242 a is disposed on the rear side of the left edge side of theengine supporting frame 237. The supporting bracket 243 a is disposed onthe front side of the right edge side of the engine supporting frame237. A hood shield plate (shielding plate) 244 covering the rear side ofthe hood 6 has a lower edge coupled to the pair of left and right columnframes 242 and 243 while being separated from the upper surfaces of theengine leg members 240.

The hood shield plate 244 has a bent shape in plan view. Morespecifically, the hood shield plate 244 includes: a rear shield surface(first shield surface) 245 that expands substantially in parallel with afront surface of a wind shield 321 from the outer side (left side) ofthe left side column frame 242 toward the right; a side shield surface(second shield surface) 246 extending forward from the right edge of therear shield surface 245; and a connecting surface (third shield surface)247 extending toward the right from the front edge of the side shieldsurface 245 to be connected to the right side column frame 243. The rearshield surface 245 is connected to the left side column frame 242, has aleft edge protruding outward (toward the left) beyond the left sidecolumn frame 242, and is disposed while being separated from the frontsurface of the wind shield 321. The side shield surface 246 is disposedon the right side of the upper surface of the engine leg member 240. Theconnecting surface 247 is coupled to the right side column frame 243 tohave the right edge matching the front surface of the right side columnframe 243.

The hood shield plate 244 is disposed on the rear surface side of thehood 6 and at least covers the rear surfaces of the exhaust gaspurifying device 224 and the exhaust pipe 227, on the inner side of thehood 6. The hood shield plate 244 protrudes toward the left beyond theleft side column frame 242, and at least covers the rear surface of theleft side (side of the exhaust manifold 204) of the diesel engine 5. Thehood shield plate 244 has both edges connected to the pair of left andright column frames 242 and 243, and thus covers the entire rear surfaceof the diesel engine 5. An area on the right side of the hood shieldplate 244 is open, and the bellows pipe 228 connected to the exhaustpipe 227 and a part of the tail pipe 229 are disposed in the area, onthe rear surface side of the hood 6.

The hood shield plate 244 covers the rear surface of the hood 6, andthus shields the heat in the engine compartment below the hood 6,whereby the side of the cabin 7 is prevented from being heated by theexhaust heat from the engine compartment. Thus, an operator in the cabin7 can comfortably operate the vehicle without being affected by theexhaust heat from the diesel engine 5 and the exhaust gas purifyingdevice 224. The hood shield plate 244 is disposed while being separatedfrom the front surface of the cabin 7, whereby a heat insulating layeris formed between the hood shield plate 244 and the cabin 7 disposedbehind the hood 6.

The hood shield plate 244 has the rear shield surface 245 provided withrecesses and protrusions at a predetermined interval, and thus shieldsnoise generated from the engine compartment below the hood 6. Morespecifically, the hood shield plate 244 has a rear surface of the rearshield surface 245 provided with rectangular protrusions 245 aprotruding rearward at a predetermined interval in the upper and lowerdirection. With the recesses and the protrusions provided on the hoodshield plate 244, noise generated from the diesel engine 5 in the enginecompartment below the hood 6 is attenuated by the recesses and theprotrusions of the hood shield plate 244 to be prevented from beingtransmitted into the cabin 7.

A pair of left and right beam frames 248 and 249 bridge between upperportions of the fan shroud 234 and the hood shield plate 244. The leftside beam frame 248 has one end (rear end) coupled to the left sidecolumn frame 242 via the rear shield surface 245 of the hood shieldplate 244. The right side beam frame 249, shorter than the left sidebeam frame 248, has one end (rear end) coupled to the right side columnframe 243 via the connecting surface 247 of the hood shield plate 244.The pair of left and right beam frames 248 and 249 each have the otherend (rear end) coupled to the upper rear surface of the fan shroud 234via a coupling bracket 234 c. The fan shroud 234 and the hood shieldplate 244 stably supported by the traveling machine body 2 are bridgedand coupled to each other by the pair of beam frames 248 and 249. Thus,the components are integrated to form a rigid engine compartment memberas a whole.

A heat shield plate 250 has both left and right edges fixed to the pairof left and right beam frames 248 and 249. The heat shield plate 250bridges between the beam frames 248 and 249 while covering an area fromintermediate portions to rear sides of the beam frames 248 and 249 belowthe hood 6. The heat shield plate 250 is disposed to cover the upperportions of the exhaust gas purifying device 224 and the exhaust pipe227 above the diesel engine 5. The heat shield plate 250 is fixed tobridge between the beam frames 248 and 249. Thus, the heat shield plate250 reinforces the beam frames 248 and 249, whereby even more rigidstructure can be achieved for the engine compartment frame. The heatshield plate 250 is disposed between the exhaust gas purifying device224 and the exhaust pipe 227 and the hood 6, whereby the hood 6 can beprevented from being heated by the exhaust heat from the enginecompartment.

The exhaust gas purifying device 224 is mounted to the upper portion ofthe diesel engine 5, and is positioned on the rear inner side of thehood 6, and the heat shield plate 250 is disposed between the hood 6 andthe exhaust gas purifying device 224. The heat shield plate 250 disposedover the exhaust gas purifying device 224 can prevent the hood 6 frombeing heated by the exhaust gas from the exhaust gas purifying device224 and the diesel engine 5. A space is formed between the hood 6 andthe heat shield plate 250, whereby the exhaust gas purifying device 224can be operated in a high temperature environment with the inside of theengine compartment below the heat shield plate 250 insulated from theouter air.

The hood shield plate 244 is provided in addition to the heat shieldplate 250, and is disposed on the rear surface side of the hood 6 tocover at least the rear surface of the exhaust gas purifying device 224.Thus, heat in the engine compartment below the hood is shielded with theheat shield plate 250 and with the hood shield plate 244, whereby theheating in the cabin 7 by the exhaust heat from the engine compartmentcan be prevented. A gap is provided between the hood shield plate 244and the heat shield plate 250, so that the heat is less likely to beaccumulated in the engine compartment below the hood 6. Thus, heatdamage on the exhaust gas purifying device 224 itself, the hood 6, andthe like can be prevented.

The diesel engine 5 is installed in the front portion of the travelingmachine body 2. The exhaust gas purifying device 224 is disposed on theupper portion of the diesel engine 5 and purifies the exhaust gas fromthe diesel engine 5. The cooling fan 206 cools the diesel engine 5 withair, and is disposed on the front surface side of the diesel engine 5.The fan shroud 234 covering the cooling fan 206 is fixed to thetraveling machine body 2. The hood 6 covers the cooling fan 206, thediesel engine 5, and the exhaust gas purifying device 224. The hoodshield plate 244 covers the rear side of the diesel engine 5 and isdisposed on the rear surface of the hood 6. The hood shield plate 244 isfixed to the traveling machine body 2. The pair of left and right beamframes 248 and 249 bridge between the upper portions of the fan shroud234 and the hood shield plate 244.

A wiper 251 that removes water drops on the wind shield 321 is pivotallysupported by the wind shield 321. The wiper 251 has a driving shaft 252inserted in the cabin 7 through the wind shield 321 and pivots about thedriving shaft 252. The driving shaft 252 of the wiper 251 has a frontside covered with the rear shield surface 245 of the hood shield plate244. More specifically, the driving shaft 252 of the wiper 251 thatperforms a wiping operation on the wind shield 321 covering the frontsurface of the cabin 7 mounted to the traveling machine body 2 iscovered with a rear portion of the upper surface of the hood 6 in frontview. Thus, rain drops can be prevented from directly falling on thedriving shaft 252 of the wiper 251 or a driving mechanism for the wiper251, and a better appearance can be achieved.

A part of the wind shield 321 is provided with a through hole 253. Ahydraulic pump 254 supported in the cabin 7 protrudes outward from thecabin 7 through the through hole 253. The through hole 253 is disposedat a position opposite to the connecting surface 247 of the hood shieldplate 244. Thus, the hydraulic pump 254 disposed while protrudingoutward from the cabin 7 through the through hole 253 can be preventedfrom interfering with the hood shield plate 244. The hood shield plate244 covers the front surface of the hydraulic pump 254, whereby theheating in the hood 6 due to heat emitted from the engine compartmentcan be prevented.

The rear shield surface 245 is disposed behind the hood shield plate244, and covers the rear side of the exhaust gas purifying device 224 tobe a high temperature heat source. Thus, a space for installing theexhaust gas purifying device 224 can be provided behind the connectingsurface 244 covering the rear side of the exhaust pipe 227. Thus, aspace for installing the hydraulic pump 254 can be provided behind theconnecting surface 244. More specifically, the hood shield plate 244 isbent to be in a crank form in plan view, whereby a wide space that isless affected by the exhaust heat from a side of the engine compartmentcan be provided on the front side of the cabin 7 (operating seat 8),whereby the hydraulic pump 254 and the like can be appropriatelydisposed.

A hood supporting bracket 255 is provided at an upper edge of the frontsurface of the hood shield plate 244 to pivotally support the rear sideof the hood 6. The hood supporting bracket 255 has both left and rightedges bent to be fixed to the rear shield surface 245 and the sideshield surface 246 of the hood shield plate 244. Thus, the hoodsupporting bracket 255 has the rear surface connected to the rear shieldsurface 245 and has the side surface extending from the right edge sideconnected to the side shield surface 246.

As illustrated in FIG. 16, the hood supporting bracket 255 has an upperend side coupled to a hinge member 263 that pivots while being coupledto and supporting the rear portion of the hood 6. The side shieldsurface 246 of the hood shield plate 244 has an upper edge side providedwith a notch portion 246 a. Thus, a part of the right side surface ofthe hood supporting bracket 255 can be accessed from the outside of thehood shield plate 244. The hood supporting bracket 255 has tacking pins255 a for tacking the hinge member 263 coupled to the hood 6 protrudingfrom the left and the right outer side surfaces. The hood supportingbracket 255 is provided with nuts 255 b to which the hinge member 263 iscoupled at positions above the tacking pins 255 a, on both left andright side surfaces.

Gas springs (hood dampers) 256 and 256 that can make a telescopicmovement are disposed on both left and right sides of the heat shieldplate 250 below the hood 6. The pair of left and right gas springs 256and 256 each have one end (rear end) pivotally supported on the rear endside of the corresponding one of the pair of left and right beam frames248 and 249, and have the other end (front end) pivotally supported tothe upper inner side surface of the hood 6. Thus, when the front portionof the hood 6 is lifted, the hood 6 is opened about the upper endposition of the hood shield plate 244, so that a maintenance work andthe like can be performed for the diesel engine 5.

The hood 6 has a front surface center position provided with the frontgrille 231 as illustrated in FIG. 1 to FIG. 4 and FIG. 17 to FIG. 23.Head lights 257 and 258 are arranged in the upper and lower direction oneach of both left and right sides of the front grille 231. The ceilingportion 259 on the upper side of the hood 6 inclines diagonally upwardfrom the front side toward the rear side. A space below the rear portionside of the ceiling portion 259 is large. Thus, a large space can beprovided for accommodating the exhaust gas purifying device 224 in theengine compartment in the hood 6. The hood 6 has an opening 268 formedon the front side of each of left and right side surface portions 269.The cooling air is taken in from both left and right sides of the hood 6through the openings 268. Furthermore, an opening 270 is formed on thefront side of the ceiling portion 259 of the hood 6, and thus thecooling air is further taken in from the front upper side of the hood 6through the opening 270.

With a space formed by arranging the heat shield plate 250 covering theupper side of the exhaust gas purifying device 224 and the ceilingportion 259 of the hood 6 sufficiently separated from each other, anexcellent heat balance can be maintained in the engine compartment.Furthermore, the front grille 231 for taking in the cooling air isdisposed in a wide area at the center of the front surface of the hood6. Thus, the cooling air can be sufficiently supplied into the enginecompartment, whereby the heat can be prevented from accumulating in thehood 6. The openings 268 and 270 are formed on the both side surfaceportions 269 of the hood 6 and on the front side of the ceiling portion259, whereby an optimum cooling structure can be achieved in the enginecompartment below the hood 6.

The engine covers 232 that are punched over the entire surfaces aredisposed in wide areas on the left and right rear lower sides of thehood 6. Thus, air heated by the diesel engine 5 and the exhaust gaspurifying device 224 can be discharged outside. An upper end position ofthe engine cover 232 is positioned below the exhaust gas purifyingdevice 224, whereby a high temperature maintaining effect can beachieved by the hood 6 for the exhaust gas purifying device 224. Thus, ahigh temperature regeneration operation can be achieved.

As illustrated in FIG. 16 to FIG. 23, the ceiling portion 259 of thehood 6 has a rear edge provided with a notch portion 260. The drivingshaft 252 of the wiper 251 is disposed on the rear side of the notchportion 260. Thus, the driving shaft 252 is covered with the rearportion of the ceiling portion 259 of the hood 6 in front view of thehood 6. The hood 6 has a rear frame 261 and an intermediate frame 262fixed to a back surface of the ceiling portion 259. The rear frame 261extends in the left and right direction to bridge between rear sides ofthe ceiling portion 259. The intermediate frame 262 extends in the leftand right direction to bridge between intermediate portions of theceiling portion 259. The rear frame 261 and the intermediate frame 262each have a shape curved along an inner circumference surface of thehood 6. The rear frame 261 and the intermediate frame 262 each have bothend portions fixed to inner side surfaces of the left and the right sidesurface portions 269 of the hood 6.

On the back surface side of the ceiling portion 259, the rear frame 261has a center position provided with a hood side coupling member(supporting member) 264 fixed by being fit on the hinge member 263 ofthe hood supporting bracket 255. A longitudinal frame 271 extends in thefront and rear direction on the ceiling portion 259 of the hood 6 tocouple between the center position of the rear frame 261 in the left andright direction and the center position of the intermediate frame 262 inthe left and right direction. The hood side coupling member 264 is alsocoupled to the longitudinal frame 271 having a rear end fixed to therear frame 261.

The ceiling portion 259 has the back surface side provided with a rearleft shielding member (shielding plate) 266 and a rear right shieldingmember (shielding plate) 267. The rear left shielding member 266 is at aleft side position on a rear end of the hinge member 263 and is anextension of the upper side of the rear shield surface 245 of the hoodshield plate 244. The rear right shielding member 267 is at a right sideposition on the rear end of the hood side coupling member (supportingmember) 264, and is an extension of the connecting surface 247 of thehood shield plate 244. A coupling plate member 272 is coupled to theback surface of the ceiling portion 259 at a position more on the rearside than the rear frame 261, and is disposed at a left side position ofthe hood side coupling member 264. The rear left shielding member 266 isconnected to a rear edge of the coupling plate member 272. The rearright shielding member 267 is connected to a rear edge of the rear frame21.

In the hood 6, shielding protrusions (shielding plates) 273 protrudefrom the inner side surfaces of the left and the right side surfaceportions 269 and extend in the upper and lower direction. The shieldingprotrusion 273 has a distal end covered with a seal member 274. Theshielding protrusions 273 are disposed at positions close to left andright portions of the radiator 235. More specifically, the shieldingplate 273 protrudes at a position more on the rear side than the opening268 of the hood 6 and extends in the upper and lower direction along therear edge of the opening 268. Thus, when the hood 6 is closed, theshielding protrusion 273 comes into contact with the side shieldingportion 234 b of the fan shroud 234 positioned on the rear surface ofthe radiator 235.

The intermediate frame 262 is provided with shafts 265 that are at upperpositions of left and right surfaces bent downward at both left andright sides of the ceiling portion 259, and protrude inward. The pair ofleft and right gas springs 256 each have a front end pivotally supportedby the left and the right shafts 265. Rods 256 a are inserted in rearends of the left and the right gas springs 256. Supporting portions 248a and 249 a are provided on rear end sides of the beam frames 248 and249 and axially support the rear ends of the rods 256 a of the gassprings 256. As illustrated in FIG. 22, the gas spring 256 has the rod256 a extended when the hood 6 is opened, and pivots about thesupporting portions 248 a and 249 a to support the front side of thehood 6 at the intermediate frame 262.

The hinge member 263 includes: a pivoting portion 275 fixed to the hood6; and a fixed portion 276 fixed to the hood shield plate 244. Thepivoting portion 275 is pivotally supported to be able to pivot aboutthe fixed portion 276. The pivoting portion 275 is fastened to the hoodside coupling member 264 fixed to the ceiling portion 259, and is fixedto the back surface of the ceiling portion 259. The fixed portion 276 isbent at both left and right edges, to have a substantially U shape(rectangular U shape) in plan view. The fixed portion 276 has left andright side surfaces each include: a notched groove 263 a formed bypartially notching the lower edge toward the upper side; and a boltinserted hole 263 b in which a bolt 255 c is inserted. The pivotingportion 275 has a rear end provided with a shaft tube 277 extending inthe left and right direction. A core rod (rotational shaft) 278 insertedin the shaft tube 277 has both left and right ends rotatably supportedby upper ends of the left and the right side surfaces of the fixedportion 276.

As illustrated in FIG. 16, the fixed portion 276 of the hinge member 263is fit to the hood supporting bracket 255 from the upper side, and isdisposed to cover the front side of the hood supporting bracket 255.Here, the tacking pins 255 a of the hood supporting bracket 255 are fitto the notched grooves 263 a of the fixed portion 276, whereby the hingemember 263 can be guided to the fixed position with respect to the hoodsupporting bracket 255. More specifically, the fixed portion 276 isfixed to the hood supporting bracket 255 with the tacking pins 255 ainserted in the notched grooves 263 a, and with inner sides of the leftand the right side surfaces of the fixed portion 276 in contact withouter sides of the left and the right side surfaces of the hoodsupporting bracket 255.

Then, nuts 255 d are screwed to the tacking pins 255 a of the hoodsupporting bracket 255, and the bolts 255 c are screwed to the nuts 255b of the hood supporting bracket 255. Thus, the hinge member 263 isfastened to the hood supporting bracket 255. More specifically, the nuts255 d are fastened to the tacking pins 255 a inserted in the notchedgrooves 263 a of the fixed portion 276, and the bolts 255 c inserted inthe bolt inserted holes 263 b of the fixed portion 276 are fastened tothe nuts 255 b. Thus, the fixed portion 276 is fixed to the hoodsupporting bracket 255. As a result, the fixed portion 276 and the hoodsupporting bracket 255 form a frame having a rectangular cross-section,whereby the hinge member 263 can be highly rigidly supported to the hoodsupporting bracket 255 so that sufficient supporting strength can beachieved when the hood 6 is opened.

The hood shield plate 244 covering the rear side of the diesel engine 5is disposed on the rear surface of the hood 6 while being fixed to thetraveling machine body 2. The heat shield plate 230 is disposed betweenthe hood 6 and the exhaust gas purifying device (post-processing device)224. The hood 6 is opened/closed by being pivoted about the upper endposition of the hood shield plate 244.

The hood shield plate 244 is disposed while being separated from thefront side of the cabin 7 disposed on the rear side of the hood 6. Thebeam frames 248 and 249 in parallel with the traveling machine body 2are disposed on both sides of the front surface of the hood shield plate244. The hood 6 includes: the hinge member 263 to which the pivotingportion 275 is connected, disposed at the rear end position of the hood6; and the damper (gas spring) 256 that has one end connected to thefront side of the hood 6 and makes telescopic movement. The fixedportion 276 of the hinge member 263 is connected to the hood supportingportion (hood supporting bracket) 255 disposed on the upper edge side ofthe hood shield plate 244. The other end of the damper 256 is rotatablysupported by the beam frames 248 and 249.

As illustrated in FIG. 17, the shielding protrusions 273 protrudingtoward the inner sides of the both side surface portions 269 of the hood6 are in contact with the side shielding portions 234 b disposed on theside surfaces of the fan shroud 234 in a state where the hood 6 isclosed. A flow of cooling air, taken in though the opening 268 formed onthe front side of the shielding protrusion 273, toward the rear side isblocked in the space on the outer side of the frame 226 and the radiator235 in the hood 6 by the shielding protrusion 273 and the side shieldingportion 234 b. Thus, the cooling air taken in through the opening 268 isforcibly sent through meshes of the mesh plate members on the frontsurface and the left and the right side surfaces of the frame 226.

As illustrated in FIG. 18, the back surface of the ceiling portion 259of the hood 6 is disposed close to the upper shielding portion 234 aprovided on the upper surface of the fan shroud 234, in the state wherethe hood 6 is closed. The flow of the cooling air taken in through theopening 270 positioned on the front side of the upper shielding portion234 a toward the rear side is partially blocked in the space on theouter side of the frame 226 and the radiator 235 in the hood 6 by theupper shielding portion 234 a. Thus, a large portion of the cooling airtaken in through the opening 268 is forcibly sent through meshes of themesh plate members on the front surface and the left and the right sidesurfaces of the frame 226.

As described above, the shielding protrusion 273 and the side shieldingportion 234 b are positioned on the rear side of the opening 268 and theupper shielding portion 234 a is disposed on the rear side of theopening 270 in the state where the hood 6 is closed. Thus, a largeamount of cooling air can be taken into the frame 226. Thus, a highereffect of cooling various cooling members such as the radiator 235 andthe intercooler disposed on the front side of the engine compartment isachieved. A large amount of cooling air can be taken in by the coolingfan 206 surrounded by the fan shroud 234. Thus, the cooling air can besupplied to the engine 5 as the heat emitting member. Thus, an excellentheat balance can be achieved in the engine compartment.

The hood 6 has the openings 268 formed on the both left and right sideportions (side surface portions) 269. The shielding plate (shieldingprotrusion) 273 is disposed at a position close to the left and theright side portions of the radiator 235. Thus, the cooling air taken inthrough the openings 268 can be sent toward the front surface side ofthe radiator 235. Thus, the radiator 235 can be efficiently cooled withthe amount of cooling air passing through the radiator 235 increased.The radiator 235 stands in a front portion of the traveling machine body2 and the fan shroud 234 surrounding the cooling fan 206 is attached onthe rear surface side of the radiator 235. Thus, the shielding plates273 provided to the hood 6 are in contact with the both left and rightside portions of the fan shroud 234 when the hood 6 is closed.

The hood 6 further has the opening 270 formed on the ceiling portion259. The fan shroud 234 includes: the upper shielding portion 234 aextending in the left and right direction on the upper surface; and thepair of left and right side shielding portions 234 b extending in theupper and lower direction on the left and the right side surfaces. Whenthe hood 6 is closed, the upper shielding portion 234 a is disposedclose to the back surface of the ceiling portion 259 of the hood 6, andthe side shielding portion 234 b is in contact with the shielding plateof the hood 6. The openings 270 and 268 formed on the ceiling portion259 and the both left and right side portions 269 of the hood 6 arepositioned more on the front side than the fan shroud 234.

The configuration of portions in the invention according to the presentapplication is not limited to that in the illustrated embodiment, andcan be modified in various ways without departing from the gist of theinvention according to the present application.

The embodiments of the invention according to the present applicationrelates to a working vehicle such as a tractor for a farming work or awheel loader for a construction work.

1. A work vehicle, comprising: an engine positioned in a front portionof a traveling machine body; and a post-processing device mounted on anupper side of the engine, the post-processing device configured topurify exhaust gas from the engine; a hood configured to cover theengine and the post-processing device; a hood shield plate positionedbetween a rear side of the post-processing device and a front side of acabin, the hood shield plate disposed adjacent to, and distinct from,the front side of the cabin; and a heat insulating layer positionedbetween the front side of the cabin and the hood shield plate.
 2. Thework vehicle according to claim 1, further comprising: a rotationalshaft positioned above the hood shield plate and configured as a pivotfulcrum; and wherein the hood is configured to rotate about therotational shaft between an open position and a closed position.
 3. Thework vehicle according to claim 1, further comprising: a radiatordisposed on a front portion of the traveling machine body; and a fanshroud surrounding a cooling fan coupled to a rear surface side of theradiator; and wherein the hood includes shielding plates that arepositioned such that the shielding plates are in contact with both aleft and a right side portion of the fan shroud while the hood is in aclosed position.
 4. A work vehicle, comprising: an engine; apost-processing device coupled to an upper side of the engine; a hoodconfigured to cover the engine and the post-processing device; a hoodshield plate positioned between a cabin of the work vehicle and thepost-processing device; and a heat insulating layer disposed between thehood shield plate and the cabin.
 5. The work vehicle according to claim4, further comprising: a radiator coupled to the engine, the enginepositioned between the radiator and the cabin; and a fan shroud coupledto the radiator and surrounding a cooling fan, the fan shroud positionedbetween the radiator and the engine.
 6. The work vehicle according toclaim 5, wherein the fan shroud includes: an upper shielding portion; aleft side shielding portion; and a right side shielding portion, each ofthe left and right side shielding portions protruding from a respectiveleft and right side surface of the fan shroud.
 7. The work vehicleaccording to claim 5, wherein: the hood is movable between an openposition and a closed position; and the hood includes: a ceiling portionconfigured to cover the upper side of the engine while the hood is in aclosed position; a first side surface portion extending from a firstside of the ceiling portion; and a second side surface portion extendingfrom a second side of the ceiling portion that is opposite the firstside.
 8. The work vehicle according to claim 7, wherein: the first sidesurface portion includes a first shielding plate that extends from aninner side of the first side surface portion; and the second sidesurface portion includes a second shielding plate that extends from aninner side of the second side surface portion.
 9. The work vehicleaccording to claim 8, wherein: the first side surface portion definesone or more first openings configured to transport air from an exteriorof the hood to an interior cavity defined by the hood when the hood isin the closed position; the second side surface portion defines one ormore second openings configured to transport air from an exterior of thehood to interior cavity; and the first and second shielding plate areeach positioned between the hood shield plate and the one or more firstand second openings while the hood is in the closed position.
 10. Thework vehicle according to claim 9, further comprising: a frame coupledto the radiator; and wherein, while the hood is closed, the firstshielding plate is configured to direct air taken in from the one ormore first openings to the frame.
 11. The work vehicle according toclaim 10, wherein the frame is configured to define a flow path totransport air to the radiator.
 12. The work vehicle according to claim8, wherein, while the hood is in the closed position, the firstshielding plate and the second shielding plate are adjacent positionedto the fan shroud.
 13. The work vehicle according to claim 12, wherein,while the hood is in the closed position, the first shielding plate isin contact with a first side of the fan shroud.
 14. The work vehicleaccording to claim 13, wherein, while the hood is in the closedposition, the second shielding plate is in contact with a second side ofthe fan shroud.
 15. The work vehicle according to claim 4, furthercomprising: a rotational shaft positioned above the hood shield plate;and wherein: the hood is configured to rotate about the rotational shaftbetween an open position and a closed position; and the post-processingdevice configured to purify exhaust gas from the engine.
 16. The workvehicle according to claim 15, further comprising: a hinge member, thehinge member including: a pivoting portion that includes the rotationalshaft, the pivoting portion coupled to the hood; and a fixed portioncoupled to the hood shield plate.
 17. The work vehicle according toclaim 16, further comprising: a hood support bracket coupled to asurface of the hood shield plate, the surface of the hood shield platefacing a rear surface of the post-processing device; and wherein thehood is coupled to the hood shield plate via the hinge member and thehood support bracket.
 18. The work vehicle according to claim 17,further comprising: a radiator coupled to the engine; and a fan shroudcoupled to the radiator, the fan shroud surrounding a cooling fan andpositioned between the radiator and the engine.
 19. The work vehicleaccording to claim 18, further comprising: a first beam frame extendingbetween the hood shield plate and an upper shielding portion of the fanshroud; and a second beam frame extending between the hood shield plateand an upper shielding portion of the fan shroud.
 20. The work vehicleaccording to claim 19, wherein the first and second beam frame arecoupled to the hood shield plate via the hood support bracket.